1. Technical Field
The invention concerns a piston ring, having a main body, which exhibits a contact surface provided with at least one chamber configuration, one upper and one lower flank surface along with one inner peripheral surface.
2. Related Art
A piston ring as well as a process for producing the same may be gleaned from DE 103 59 802 B3. The piston ring contains a contact surface provided with a contact surface profile along with one upper and one lower flank surface, wherein at least the contact surface is provided with a vapor deposit coating, in such a way that a portion of the contact surface is provided with a removable mask, so that after production of the vapor deposit coating and removal of the mask a substantially sharp-edged contact edge is provided between the contact surface and at least one of the flank surfaces.
In order to achieve good oil consumption and break-out behavior it is necessary for the lower edge at the transition from the ring contact surface to the ring flank to be designed so that the edges are as sharp as possible. In the case of coated piston rings these requirements prove to be increasingly difficult, dependent upon the coating thickness of the contact surface layer.
Well known solutions for this problem are rings which are single-sided and full of chambers, in which the coating is only deposited in the central to upper, or only in the central area of the contact surface. The critical edge is formed by the base material and due to this proves to be completely sharp-edged.